Display device and electronic apparatus

ABSTRACT

A display device includes a plurality of signal lines that are so juxtaposed as to be extended along one direction, a plurality of common drive electrodes that are so juxtaposed as to be extended along the signal lines, and a plurality of display elements that are each connected to a respective one of the plurality of signal lines and are each connected also to the common drive electrode that makes a pair with the connected signal line. Scan driving of the plurality of display elements is performed in the direction of the signal lines.

BACKGROUND

The present disclosure relates to display devices, and particularly to adisplay device configured with a liquid crystal display element andelectronic apparatus including such a display device.

In recent years, the liquid crystal display device has become themainstream of the display device in terms of low power consumption andspace saving. Some liquid crystal display devices include a commonelectrode that gives a common potential to plural pixels and a pixelelectrode that is so provided for each pixel as to be opposed to thecommon electrode with the intermediary of a liquid crystal layer, forexample. In such a liquid crystal display device, for example, inversiondriving is performed by applying a pixel signal to the pixel electrodeand applying a rectangular wave signal to the common electrode, anddisplaying is performed by changing the orientation of liquid crystalmolecules based on the difference between the potential of the pixelelectrode and the potential of the common electrode (pixel potential).

In some of the liquid crystal display devices, ingenuity is exercised onthe common electrode. For example, Japanese Patent Laid-open No.2009-251608 proposes a liquid crystal display device including pluralcommon electrodes that are extended along the row direction of thedisplay surface and juxtaposed in the column direction. In this liquidcrystal display device, e.g. in the case of applying a drive signal tothe common electrode in order to perform inversion driving, the drivesignal is applied only to the common electrode relating to the pixels inone horizontal line in which the pixel signal is written. This allowsreduction in the power consumption in the driving of the commonelectrode.

SUMMARY

The common electrode generally should have optical transparency and isoften formed by using indium tin oxide (ITO). Such a common electrodehas higher resistance and larger time constant compared with the case ofusing a metal such as aluminum. In this case, in writing of the pixelsignal to pixels, this pixel signal travels to the common electrode andwriting to adjacent pixels in the same one horizontal line is disturbed,so that possibly the image quality is deteriorated due to thiscrosstalk.

Furthermore, the drive circuit to drive the common electrode is desiredto perform driving with low output impedance for the common electrode.However, depending on the arrangement of this drive circuit, its outputimpedance becomes high because of e.g. a long length of a power supplyline to this drive circuit, and thus possibly driving the commonelectrode becomes difficult and the image quality is deteriorated.

There is a need for a technique to provide a display device andelectronic apparatus capable of suppressing the deterioration of theimage quality attribute to the common electrode.

According to an embodiment of the present disclosure, there is provideda display device including a plurality of signal lines, a plurality ofcommon drive electrodes, and a plurality of display elements. Theplurality of signal lines are so juxtaposed as to be extended along onedirection. The plurality of common drive electrodes are so juxtaposed asto be extended along the signal lines. The plurality of display elementsare each connected to a respective one of the plurality of signal linesand are each connected also to the common drive electrode that makes apair with the connected signal line. Scan driving of the plurality ofdisplay elements is performed in the direction of the signal lines.

According to another embodiment of the present disclosure, there isprovided electronic apparatus including the above-described displaydevice. Examples of the electronic apparatus include a televisiondevice, a digital camera, a personal computer, a video camcorder, and aportable terminal device typified by a cellular phone.

In the display device and the electronic apparatus of the embodiments ofthe present disclosure, scan driving of the display elements isperformed in the direction of the signal lines. In this scan driving, tothe plural display elements simultaneously driven, a signal forperforming displaying is supplied from each of the signal line and thecommon drive electrode, which are extended along the same direction,separately.

According to further embodiment of the present disclosure, there isprovided a display device including a plurality of signal linesconfigured to be so juxtaposed as to be extended along a firstdirection, a plurality of drive electrodes configured to be sojuxtaposed as to be extended along the first direction, and a pluralityof display elements configured to be subjected to scan driving in thefirst direction.

According to the display device and the electronic apparatus of theembodiments of the present disclosure, the common drive electrodes areso disposed as to be extended along the signal lines and displaying isperformed by scan driving in the direction of the signal lines. Thus,the deterioration of the image quality attributed to the commonelectrode can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing one configuration example of a displaydevice according to an embodiment of the present disclosure;

FIG. 2 is a block diagram showing one configuration example of aselection switch unit shown in FIG. 1;

FIG. 3 is a sectional view showing the schematic sectional structure ofa display unit shown in FIG. 1;

FIG. 4 is a circuit diagram showing one configuration example of thedisplay unit shown in FIG. 1;

FIG. 5 is an explanatory diagram showing one configuration example of adrive electrode shown in FIG. 4;

FIGS. 6A and 6B are schematic diagrams showing examples of mounting ofthe display device shown in FIG. 1 into a module;

FIGS. 7A to 7E are timing waveform diagrams showing one operationexample of the display device shown in FIG. 1;

FIGS. 8A and 8B are schematic diagrams showing one operation example ofthe display device shown in FIG. 1;

FIGS. 9A and 9B are circuit diagrams for explaining the operation of thedisplay device shown in FIG. 1;

FIG. 10 is a circuit diagram showing one configuration example of thedisplay unit according to a comparative example;

FIG. 11 is a schematic diagram showing an example of mounting of thedisplay device according to the comparative example into a module;

FIGS. 12A to 12D are timing waveform diagrams showing one operationexample of the display device according to the comparative example;

FIGS. 13A and 13B are circuit diagrams for explaining the operation ofthe display device according to the comparative example;

FIGS. 14A and 14B are characteristic diagrams showing characteristics ofthe display devices according to the embodiment and the comparativeexample;

FIG. 15 is an explanatory diagram showing one configuration example ofthe drive electrode according to a modification example;

FIGS. 16A and 16B are explanatory diagrams showing one configurationexample of the drive electrode according to another modificationexample;

FIG. 17 is an explanatory diagram showing one configuration example ofthe drive electrode according to another modification example;

FIGS. 18A and 18B are schematic diagrams showing one operation exampleof the display device according to another modification example;

FIG. 19 is a perspective view showing the appearance configuration ofapplication example 1 of pieces of electronic apparatus to which theembodiment is applied;

FIGS. 20A 20B are perspective views showing the appearance configurationof application example 2;

FIG. 21 is a perspective view showing the appearance configuration ofapplication example 3,

FIG. 22 is a perspective view showing the appearance configuration ofapplication example 4;

FIGS. 23A to 23G are front view, side view, top view, and bottom viewshowing the appearance configuration of application example 5; and

FIG. 24 is a sectional view showing the schematic sectional structure ofthe display unit according to another modification example.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of the present disclosure will be described in detailbelow with reference to the drawings. The order of the description is asfollows.

-   1. Embodiment-   2. Application Examples

1. EMBODIMENT Configuration Example Overall Configuration Example

FIG. 1 shows one configuration example of a display device according toan embodiment of the present disclosure. A display device 1 is a liquidcrystal display device configured with use of a liquid crystal displayelement as a display element. The display device 1 includes a controller11, a gate driver 12, a source driver 13, a selection switch unit 14, adrive signal generator 15, a drive electrode driver 16, and a displayunit 20.

The controller 11 is a circuit that supplies a control signal to each ofthe gate driver 12, the source driver 13, the drive signal generator 15,and the drive electrode driver 16 based on a video signal Vdisp suppliedfrom the external and controls them so that they may operate insynchronization with each other. Specifically, the controller 11supplies a display scan timing control signal to the gate driver 12 andsupplies a video signal and a display timing control signal to thesource driver 13. In addition, the controller 11 supplies a drive signaltiming control signal to the drive signal generator 15 and the driveelectrode driver 16.

The gate driver 12 has a function to sequentially select one horizontalline as the subject of display driving of the display unit 20 based onthe control signal supplied from the controller 11. Specifically, asdescribed later, the gate driver 12 applies a scan signal Vscan to thegates of TFT elements Tr in pixels Pix via a scan signal line GCL tothereby sequentially select one row (one horizontal line) of the pixelsPix formed in a matrix manner in the display unit 20 as the subject ofdisplay driving.

The source driver 13 generates and outputs a pixel signal Vsig based onthe video signal and the control signal supplied from the controller 11.Specifically, as described later, the source driver 13 generates, fromthe video signal for one horizontal line, the pixel signal Vsig obtainedby time-division multiplexing of pixel signals Vpix of plural (in thisexample, three) sub-pixels SPix of the display unit 20 and supplies thepixel signal Vsig to the selection switch unit 14. Furthermore, thesource driver 13 generates switch control signals VselR, VselG, andVselB used to separate the pixel signals Vpix multiplexed into the pixelsignal Vsig and supplies these signals to the selection switch unit 14together with the pixel signal Vsig. This multiplexing is carried out toreduce the number of interconnects between the source driver 13 and theselection switch unit 14.

The selection switch unit 14 separates the pixel signals Vpix subjectedto the time-division multiplexing into the pixel signal Vsig based onthe pixel signal Vsig and the switch control signals VselR, VselG, andVselB supplied from the source driver 13, and supplies the pixel signalsVpix to the display unit 20.

FIG. 2 shows one configuration example of the selection switch unit 14.The selection switch unit 14 has plural switch groups 17. In thisexample, each switch group 17 is composed of three switches SWR, SWG,and SWB. One terminals of these switches are connected to each other andsupplied with the pixel signal Vsig from the source driver 13, and theother terminals are each connected to a respective one of the sub-pixelsSPix corresponding to red (R), green (G), and blue (B) via a pixelsignal line SGL of the display unit 20. These three switches SWR, SWG,and SWB are on/off-controlled by the switch control signals VselR,VselG, and VselB supplied from the source driver 13. Based on thisconfiguration, the selection switch unit 14 sequentially turns thesethree switches to the on-state in a time-division manner in response tothe switch control signals VselR, VselG, and VselB to thereby functionto separate the pixel signals Vpix (VpixR, VpixG, VpixB) from the pixelsignal Vsig obtained by multiplexing. Furthermore, the selection switchunit 14 supplies these pixel signals Vpix to three sub-pixels SPix.

The drive signal generator 15 generates a drive signal Vcom with analternate current (AC) rectangular waveform based on the control signalsupplied from the controller 11 and supplies it to the drive electrodedriver 16.

The drive electrode driver 16 is a circuit that supplies the drivesignal Vcom to common drive electrodes COML (described later) of thedisplay unit 20 based on the control signal supplied from the controller11. Specifically, the drive electrode driver 16 applies the drivesignals Vcom having AC rectangular waveforms with polarities opposite toeach other to the common drive electrodes COML adjacent to each other asdescribed later. In association with this, the pixel signals Vpix withpolarities opposite to each other are applied to the sub-pixels SPixadjacent to each other. That is, in this example, the display unit 20 isdriven by so-called dot-inversion driving (sub-pixel-inversion driving).

The display unit 20 is configured with use of the liquid crystal displayelement and performs displaying through sequential scanning of each onehorizontal line based on the pixel signal Vpix, the scan signal Vscan,and the drive signal Vcom as described later.

FIG. 3 shows an example of the sectional structure of the major part ofthe display unit 20. This display unit 20 includes a pixel substrate 2,a counter substrate 3 disposed opposed to this pixel substrate 2, and aliquid crystal layer 6 interposed between the pixel substrate 2 and thecounter substrate 3.

The pixel substrate 2 has a TFT substrate 21 as a circuit board andplural pixel electrodes 22 arranged in a matrix on this TFT substrate21. On the TFT substrate 21, thin film transistors (TFT) of therespective pixels and interconnects such as the pixel signal line SGL tosupply the pikel signal Vpix to each pixel electrode 22 and the scansignal line GCL to drive each TFT are formed although not shown in thedrawing.

The counter substrate 3 has a glass substrate 31, a color filter 32formed on one surface of this glass substrate 31, and the plural commondrive electrodes COML formed on this color filter 32. The color filter32 is configured by periodically arranging color filter layers of e.g.three colors of red (R), green (G), and blue (B) and three colors of R,G, and B are associated with each display pixel as one set. The commondrive electrode COML functions as the common drive electrode of thedisplay unit 20. The common drive electrode COML is coupled to the TFTsubstrate 21 by a contact electrically-conductive pillar (not shown) andthe drive signal Vcom having an AC rectangular waveform is applied fromthe TFT substrate 21 to the common drive electrode COML via this contactelectrically-conductive pillar. A polarizer 35 is disposed on the othersurface of the glass substrate 31.

The liquid crystal layer 6 modulates light passing through it dependingon the state of an electric field. For example, a liquid crystal of anyof various modes such as twisted nematic (TN), vertical alignment (VA),and electrically controlled birefringence (ECB) modes is used.

An alignment film is provided between the liquid crystal layer 6 and thepixel substrate 2 and between the liquid crystal layer 6 and the countersubstrate 3, and an incidence-side polarizer is disposed on the lowersurface side of the pixel substrate 2. In FIG. 3, diagrammaticrepresentation of these components is omitted.

FIG. 4 shows a configuration example of the pixel structure in thedisplay unit 20. The display unit 20 has the plural pixels Pix arrangedin a matrix. Each pixel Pix is composed of three sub-pixels SPix. Thesethree sub-pixels SPix are so disposed as to each correspond to arespective one of three colors (RGB) of the color filter 32 shown inFIG. 3. The sub-pixel SPix has the TFT element Tr, a liquid crystalelement LC, and a holding capacitance element Cs. The TFT element Tr isformed of a thin film transistor. In this example, it is formed of ann-channel metal oxide semiconductor (MOS) TFT. The source of the TFTelement Tr is connected to the pixel signal line SGL. The gate isconnected to the scan signal line GCL and the drain is connected to oneterminal of the liquid crystal element LC. One terminal of the liquidcrystal element LC is connected to the drain of the TFT element Tr andthe other terminal is connected to the common drive electrode COML. Theholding capacitance element Cs is to hold the potential differenceacross the liquid crystal element LC. One terminal thereof is connectedto the drain of the TFT element Tr and the other terminal is connectedto the common drive electrode COML.

The sub-pixel SPix is connected to the other sub-pixels SPix that belongto the same row of the display unit 20 by the scan signal line GCL. Thescan signal line GCL is connected to the gate driver 12 and suppliedwith the scan signal Vscan by the gate driver 12. Furthermore, thesub-pixel SPix is connected to the other sub-pixels SPix that belong tothe same column of the display unit 20 by the pixel signal line SGL. Thepixel signal line SGL is connected to the selection switch unit 14 andsupplied with the pixel signal Vpix by the selection switch unit 14.

Moreover, the sub-pixel SPix is connected to the other sub-pixels SPixthat belong to the same column of the display unit 20 by the commondrive electrode COML. The common drive electrode COML is connected tothe drive electrode driver 16 and supplied with the drive signal Vcom bythe drive electrode driver 16.

FIG. 5 shows one configuration example of the common drive electrodeCOML. In this example, the common drive electrodes COML are so formed asto be extended along the same direction as that of the pixel signallines SGL, and the plural sub-pixels SPix that belong to the same onecolumn share one common drive electrode COML. Each common driveelectrode COML is connected to the drive electrode driver 16 via a driveelectrode line part 29. That is, the drive electrode driver 16 suppliesthe drive signal Vcom in units of the sub-pixel SPix.

Based on this configuration, in the display unit 20, the gate driver 12drives the scan signal lines GCL in such a manner as toline-sequentially scan them in a time-division manner and thereby onehorizontal line is sequentially selected. In addition, the selectionswitch unit 14 supplies the pixel signal Vpix to the pixels Pix thatbelong to this one horizontal line and thereby displaying is performedon each one horizontal line basis.

FIGS. 6A and 6B schematically show mounting of the display device 1 intoa display module: FIG. 6A shows one example of the mounting and FIG. 6Bshows another example.

A display module 5A shown in FIG. 6A has the display unit 20, a chip onglass (COG) 19, gate drivers 12A and 12B, and the selection switch unit14. As schematically shown in FIG. 6A, in the display unit 20, thecommon drive electrodes COML are so formed as to be extended along thesame direction as that of the pixel signal lines SGL. The COG 19 is achip mounted on the TFT substrate 21 and includes the respectivecircuits used for display operation, such as the controller 11, thesource driver 13, the drive signal generator 15, and the drive electrodedriver 16 shown in FIG. 1. The gate drivers 12A and 12B are equivalentto the gate driver 12 shown in FIG. 1 and are so configured as to applythe scan signal Vscan to the scan signal line SGL from both sides of thedisplay unit 20. The gate drivers 12A and 12B and the selection switchunit 14 are formed on the TFT substrate 21, which is a glass substrate.

A display module 5B shown in FIG. 6B includes a drive electrode driver16B on the opposite side to a terminal part T of the display unit 20.This drive electrode driver 16B is provided to assist the driveelectrode driver 16 included in the COG 19. Based on this configuration,in the display module 5B, the drive electrode driver 16 in the COG 19and the drive electrode driver 16B apply the drive signal Vcom to thecommon drive electrode COML from both sides of the display unit 20.

As shown in FIGS. 6A and 6B, the common drive electrodes COML areconnected to the COG 19 including the drive electrode driver 16 across ashort distance. The drive electrode driver 16 is formed in the same COG19 as that of the drive signal generator 15, which generates the drivesignal Vcom. The COG 19 is disposed at a position near the terminal partT to supply the power of the COG 19. This allows the drive electrodedriver 16 to drive the common drive electrodes COML with low outputimpedance.

The pixel signal line SGL is equivalent to one specific example of the“signal line” in the present disclosure. The common drive electrode COMLis equivalent to one specific example of the “common drive electrode” inthe present disclosure. The liquid crystal element LC is equivalent toone specific example of the “display element” in the present disclosure.The drive electrode driver 16 is equivalent to one specific example ofthe “driver” in the present disclosure.

[Operation and Effect]

The operation and effect of the display device 1 of the presentembodiment will be described below.

(Outline of Overall Operation)

The controller 11 supplies the control signal to each of the gate driver12, the source driver 13, the drive signal generator 15, and the driveelectrode driver 16 based on the video signal Vdisp supplied from theexternal and controls them so that they may operate in synchronizationwith each other. The gate driver 12 generates the scan signal Vscan andsupplies it to the display unit 20. The source driver 13 generates thepixel signal Vsig obtained by multiplexing of the pixel signals Vpix andthe switch control signals VselR, VselG, and VselB corresponding to thepixel signal Vsig and supplies these signals to the selection switchunit 14. The selection switch unit 14 generates the pixel signals Vpixby separation based on the pixel signal Vsig and the switch controlsignals VselR, VselG, and VselB and supplies them to the display unit20. The drive signal generator 15 generates the drive signal Vcom andsupplies it to the drive electrode driver 16. The drive electrode driver16 applies the drive signal Vcom to the common drive electrode COML ofthe display unit 20. The display unit 20 performs line-sequentialscanning on each one horizontal line basis based on the supplied pixelsignal Vpix, scan signal Vscan, and drive signal Vcom to thereby displaythe image corresponding to the video signal Vdisp.

(Detailed Operation)

The detailed operation of the display device 1 will be described belowwith use of several diagrams.

FIGS. 7A to 7E show timing waveform examples of the display device 1.Specifically, FIG. 7A shows the waveform of the drive signal Vcom. FIG.7B shows the waveform of the scan signal Vscan. FIG. 7C shows thewaveform of the pixel signal Vsig. FIG. 7D shows the waveforms of theswitch control signals VselR, VselG, and VselB. FIG. 7E shows thewaveforms of the pixel signals VpixR, VpixG, and VpixB.

The display device 1 carries out display operation by dot-inversiondriving (sub-pixel-inversion driving) based on the drive signal Vcom,the scan signal Vscan, and the pixel signal Vsig. Details of theoperation will be described below.

First, at timing t1, the drive signal generator 15 inverts the drivesignal Vcom and the drive electrode driver 16 applies this drive signalVcom to the common drive electrode COML (FIG. 7A).

Next, at timing t2, the gate driver 12 applies the scan signal Vscan(n)to the scan signal line GCL for the pixels Pix on the n-th row and thescan signal Vscan(n) changes from the low level to the high level (FIG.7B). Thereby, the TFT elements Tr of the pixels Pix on the n-th rowbecome the on-state and one horizontal line in which writing operationis carried out in the display unit 20 is selected.

Next, the source driver 13 outputs the pixel signal Vsig and the switchcontrol signals VselR, VselG, and VselB. Specifically, first, at timingt3, the source driver 13 outputs a voltage VR for the sub-pixel SPix ofred (R) (FIG. 7C) and changes the switch control signal VselR from thelow level to the high level (FIG. 7D). At this time, the switch SWR ineach of the switch groups 17 of the selection switch unit 14 becomes theon-state and the pixel signal VpixR (voltage VR) is supplied to thepixel signal line SGL connected to the switch SWR (FIG. 7E). Thereafter,when the switch control signal VselR changes from the high level to thelow level, the switch SWR becomes the off-state and the pixel signalline SGL connected to the switch SWR becomes the floating state. Thus,the pixel signal VpixR is kept. Similarly, at timing t4, the sourcedriver 13 outputs a voltage VG for the sub-pixel SPix of green (G) (FIG.7C) and changes the switch control signal VselG from the low level tothe high level (FIG. 7D) to thereby supply the pixel signal VpixG(voltage VG) to the pixel signal line SGL connected to the switch SWG(FIG. 7E). Subsequently, at timing t5, the source driver 13 outputs avoltage VB for the sub-pixel SPix of blue (B) (FIG. 7C) and changes theswitch control signal VselB from the low level to the high level (FIG.7D) to thereby supply the pixel signal VpixB (voltage VB) to the pixelsignal line SGL connected to the switch SWB (FIG. 7E).

In the pixels Pix in one horizontal line, the pixel signals Vpix (VpixR,VpixG, VpixB) are supplied via the pixel signal lines SGL in theabove-described manner and thereby writing is performed.

Thereafter, at timing t6, the gate driver 12 changes the scan signalVscan(n) from the high level to the low level (FIG. 7B). Thereby, theTFT elements Tr of the pixels Vpix on the n-th row become the off-state,so that the writing operation is ended.

From then on, by repeating the above-described operation, the displaydevice 1 carries out the writing operation for the whole displaysurface.

FIGS. 8A and 8B schematically show the dot-inversion driving.Specifically, FIG. 8A shows the polarities of the pixel potentials forthe sub-pixels SPix in a certain frame. FIG. 8B show the polarities ofthe pixel potentials in the next frame. The pixel potential refers tothe potential difference between the pixel signal Vpix and the drivesignal Vcom in the sub-pixel SPix. As shown in FIGS. 8A and 8B, in thedot-inversion driving, driving is performed in such a manner that thepolarities of the pixel potentials of the sub-pixels SPix adjacent toeach other are different from each other in a certain frame.Furthermore, the polarities of the pixel potentials of all of thesub-pixels SPix are inverted on a frame-by-frame basis.

In this dot-inversion driving, the drive electrode driver 16 applies thedrive signals Vcom having AC rectangular waveforms with polaritiesopposite to each other to the common drive electrodes COML adjacent toeach other. Furthermore, in association with this operation of the driveelectrode driver 16, the source driver 13 and the selection switch unit14 apply the pixel signals Vpix with polarities opposite to each otherto the pixel signal lines SGL adjacent to each other.

In this manner, in the display device 1, the drive signal Vcom issupplied from each of the different common drive electrodes COML to arespective one of the sub-pixels SPix in one horizontal line that isselected by the scan signal Vscan and in which the pixel signal Vpix iswritten. That is, in the writing operation, the drive signal Vcom isindependently supplied to each of the sub-pixels SPix in this onehorizontal line. This can reduce the possibility that noise is mixedfrom the other sub-pixels SPix in this one horizontal line via thecommon drive electrode COML.

Next, the load of the drive electrode driver 16 will be described below.

FIGS. 9A and 9B show the equivalent circuit of the display unit 20.Specifically, FIG. 9A shows the case in which the TFT elements Tr are inthe off-state. FIG. 9B shows the case in which the TFT elements Tr arein the on-state. A capacitive element Clc is an equivalent element whenthe liquid crystal element LC is regarded as a capacitive element.

When the scan signal Vscan at the low level is applied to the scansignal line GCL and the TFT element Tr is in the off-state, the TFTelement Tr can be replaced by a capacitive element Cds corresponding tothe parasitic capacitance between the drain and the source as shown inFIG. 9A. At this time, the load from the viewpoint of the common driveelectrode COML in each sub-pixel SPix is series capacitance made withparallel capacitance (Clc+Cs) of the capacitive elements Clc and Cs andthe capacitive element Cds. In general, the capacitance Cds issufficiently lower than the capacitance (Clc+Cs) and therefore thisseries capacitance is almost equal to the capacitance Cds. That is, theload from the viewpoint of the common drive electrode COML in thesub-pixel SPix in which the TFT element Tr is in the off-state is alight capacitive load.

On the other hand, when the scan signal Vscan at the high level isapplied to the scan signal line GCL and the TFT element Tr is in theon-state, the TFT element Tr can be replaced by a resistive element Roncorresponding to the on-resistance between the drain and the source asshown in FIG. 9B. In general, this on-resistance is sufficiently low andtherefore the capacitance (Clc+Cs) is dominant in the load from theviewpoint of the common drive electrode COML in each sub-pixel SPix.That is, the load from the viewpoint of the common drive electrode COMLin the sub-pixel SPix in which the TFT element Tr is in the on-state isa heavy capacitive load.

In the display device 1, always writing is performed in only onesub-pixel SPix of the sub-pixels SPix connected to a respective one ofthe common drive electrodes COML. That is, the total load from theviewpoint of the common drive electrode COML in the display unit 20 isthe sum of the heavy capacitive load of the sub-pixel SPix in onehorizontal line as the writing subject and the light capacitive loads ofthe other sub-pixels SPix. That is, the sub-pixel SPix with the heavycapacitive load is only one sub-pixel for each common drive electrodeCOML. This makes it easier for the drive electrode driver 16 to drivethe common drive electrodes COML.

Comparison with Comparative Example

The effect of the present embodiment will be described below based oncomparison with a comparative example.

First, a display device 1R according to the comparative example will bedescribed. In the present embodiment (FIG. 4), the common driveelectrodes COML are so formed as to be extended along the same directionas that of the pixel signal lines SGL. Instead of this, the common driveelectrodes COML are so formed as to be extended along a directionintersecting with the pixel signal lines SGL in the present comparativeexample. That is, the display device 1R is configured with use of adisplay unit 20R in which the common drive electrodes COML are formed inthis manner. The other configuration is the same as that of the presentembodiment (FIG. 1).

FIG. 10 shows a configuration example of the pixel structure in thedisplay unit 20R. As shown in FIG. 10, in the display unit 20R, thecommon drive electrodes COML are so formed as to be extended along adirection intersecting with the pixel signal lines SGL and the sub-pixelSPix is connected to the other sub-pixels SPix that belong to the samerow of the display unit 20R by the common drive electrode COML. That is,the plural sub-pixels SPix that belong to the same one row share onecommon drive electrode COML.

FIG. 11 schematically shows mounting of the display device 1R into adisplay module 5R. The display module 5R has the display unit 20R, driveelectrode drivers 16RA and 16RB, and a COG 19R. In the display unit 20Raccording to the present comparative example, the common driveelectrodes COML are so formed as to be extended along a directionintersecting with the pixel signal lines SGL as schematically shown inFIG. 11. The drive electrode drivers 16RA and 16RB (hereinafter,referred to also as drive electrode drivers 16R collectively) areequivalent to the drive electrode driver 16 shown in FIG. 1 and are soconfigured as to apply the drive signal Vcom to the common driveelectrode COML from both sides of the display unit 20R. The COG 19Rincludes the respective circuits used for display operation, such as thecontroller 11, the source driver 13, and the drive signal generator 15shown in FIG. 1. Specifically, in the display device 1 according to thepresent embodiment (FIG. 6A), the drive electrode driver 16 is formed inthe COG 19. In contrast, in the display device 1R according to thepresent comparative example (FIG. 11), the drive electrode drivers 16Rare formed not in the COG 19R but on the TFT substrate 21 on both sidesof the display unit 20R in order to connect the drive electrode drivers16R to the common drive electrodes COML across a short distance.

(Crosstalk Noise)

In the display device 1R, the drive signal Vcom is supplied from thesame common drive electrode COML to each of the sub-pixels SPix in onehorizontal line that is selected by the scan signal Vscan and in whichthe pixel signal Vpix is written. That is, in the writing operation, thedrive signal Vcom is supplied to the respective sub-pixels SPix in thisone horizontal line via the common drive electrode COML. Thus, possiblynoise (crosstalk noise) is mixed from the other sub-pixels SPix in thisone horizontal line via the common drive electrode COML. Details of thisphenomenon will be described below.

FIGS. 12A to 12D show timing waveform examples of the display device 1R.Specifically, FIG. 12A shows the waveform of the scan signal Vscan. FIG.12B shows the waveforms of the switch control signals VselR, VselG, andVselB. FIG. 12C shows the waveforms of the pixel signals VpixR, VpixG,and VpixB. FIG. 12D shows the waveform of the drive signal Vcom. Thetiming waveform examples of FIGS. 12A to 12D correspond to operation ofwriting the pixel signals Vpix (VpixR, VpixG, VpixB) to one horizontalline relating to the pixels Pix on the n-th row of the display unit 20R.

In the display device 1R, at timing t11, the drive signal generator 15and the drive electrode drivers 16R invert the drive signal Vcom(n)relating to the pixels Pix on the n-th row to set it to the low voltagelevel (FIG. 12D). Thereafter, during the period from timing t12 totiming t16, the gate driver 12 sets the scan signal Vscan(n) relating tothe pixels Pix on the n-th row to the high level to thereby select onehorizontal line in which writing operation is carried out (FIG. 12A). Inthis period, the source driver 13 and the selection switch unit 14sequentially apply the pixel signals VpixR, VpixG, and VpixB to thepixel signal line SGL. In this example, the pixel signal VpixR changesto a high voltage level simultaneously with turning of the switchcontrol signal VselR to the high level and the pixel signal VpixBchanges to a high voltage level simultaneously with turning of theswitch control signal VselB to the high level. On the other hand, thepixel signal VpixG changes to a slightly high voltage levelsimultaneously with turning of the switch control signal VselG to thehigh level. That is, the potential difference between the pixel signalVpix (VpixR, VpixG, VpixB) and the drive signal Vcom (pixel potential)is large in the sub-pixels SPix of red (R) and blue (B) and is small inthe sub-pixel SPix of green (G). For example if the display unit 20R isthe normally-black type, this state means that lighting with highluminance is obtained from the sub-pixels SPix of red (R) and blue (B)and lighting with low luminance is obtained from the sub-pixel SPix ofgreen (G).

As shown in FIG. 12D, the drive signal Vcom includes a large amount ofnoise superimposed on the original AC rectangular waveform like thatshown in FIG. 7A. For example, at the timings t12 and t16, thetransition of the scan signal Vscan(n) appears as noise in the drivesignal Vcom via parasitic capacitance between the scan signal line SGLand the common drive electrode COML. Furthermore, in the period from thetiming t13 to the timing t16, the transition of the pixel signal Vpix(particularly pixel signals VpixR and VpixB) is propagated from thepixel electrode 22 to the common drive electrode COML via thecapacitances Clc and Cs for example, and appears as noise in the drivesignal Vcom.

Due to the influence of this noise, the drive signal Vcom(n) is not atits originally-designed voltage (−Vc) in the period from the timing t14to the timing t15. Specifically, the voltage level of the drive signalVcom(n) is somewhat higher than the originally-designed voltage (−Vc)(waveform part W1) due to the influence of the transition of the pixelsignal VpixR in the period from the timing t13 to the timing t14.Therefore, although the pixel signal VpixG is applied in this period,insufficiency of the writing occurs and the luminance of the sub-pixelSPix of green (G) is lower than the desired value. As just described, ifwriting is performed through application of the pixel signal Vpix whenthe voltage level of the drive signal Vcom deviates from theoriginally-designed voltage, the luminance of this sub-pixel SPixdeviates from the desired value.

In the display device 1R, the common drive electrodes COML are so formedas to be extended along a direction intersecting with the pixel signallines SGL and the drive signal Vcom is supplied from the same commondrive electrode COML to each of the sub-pixels SPix in one horizontalline in which writing operation is carried out. This causes apossibility that, in the writing operation, noise is mixed from theother sub-pixels SPix in this one horizontal line via the common driveelectrode COML and the luminance deviates from the desired value. Thatis, in the display device 1R, possibly the occurrence of this crosstalknoise leads to the lowering of the image quality.

In contrast, in the display device 1 according to the presentembodiment, the common drive electrodes COML are so formed as to beextended along the same direction as that of the pixel signal lines SGLand the drive signal Vcom is supplied from each of the different commondrive electrodes COML to a respective one of the sub-pixels SPix in onehorizontal line in which writing operation is carried out. This canreduce the possibility that, in the writing operation, noise is mixedfrom the other sub-pixels SPix in this one horizontal line via thecommon drive electrode COML, and thus can suppress the lowering of theimage quality due to crosstalk noise.

(Load of Drive Electrode Driver 16R)

The load of the drive electrode driver 16R in the present comparativeexample will be described below.

FIGS. 13A and 13B show the equivalent circuit of the display unit 20Raccording to the comparative example. Specifically, FIG. 13A shows thecase in which the TFT elements Tr are in the off-state. FIG. 13B showsthe case in which the TFT elements Tr are in the on-state.

The load from the viewpoint of the common drive electrode COML in eachsub-pixel SPix is the same as that in the display device 1 of thepresent embodiment (FIGS. 9A and 9B). Specifically, when the TFT elementTr is in the off-state (writing operation is not carried out), as shownin FIG. 13A, this load is series capacitance made with parallelcapacitance (Clc+Cs) of the capacitive elements Clc and Cs and thecapacitive element Cds, and thus is a light capacitive load almost equalto the capacitance Cds. When the TFT element Tr is in the on-state(writing operation is carried out), this load is a heavy capacitive loadalmost equal to the capacitance (Clc+Cs) as shown in FIG. 13B.

However, in the display device 1R, the common drive electrodes COML areso formed as to be extended along a direction intersecting with thepixel signal lines SGL differently from the display device 1. Therefore,in the rows in which writing operation is not carried out, writing iscarried out in none of all the sub-pixels SPix connected to therespective common drive electrodes COML. In the row in which writingoperation is carried out, writing is carried out in all the sub-pixelsSPix connected to the corresponding common drive electrode COML.Specifically, as shown in FIG. 13A, the total load of the common driveelectrode COML relating to the row in which writing is not performed inthe display unit 20R is the sum of the light capacitive loads of all thesub-pixels SPix that belong to this row. In contrast, as shown in FIG.13B, the total load of the common drive electrode COML relating to therow in which writing is performed in the display unit 20R is the sum ofthe heavy capacitive loads of all the sub-pixels SPix that belong tothis row. That is, the total load of the common drive electrode COMLgreatly differs depending on whether or not writing is performed. Inparticular, the total load is a very large capacitive load when writingis performed. The drive electrode driver 16R needs to be so configuredas to be capable of driving this very large capacitive load when writingis performed, and therefore possibly the circuit area and the powerconsumption increase in order to realize strong driving force.

Furthermore, in the display device 1R, as shown in FIG. 11, the driveelectrode drivers 16R are disposed at positions distant from the COG19R, in which the drive signal generator 15 is formed, and the terminalpart T, to which power is supplied. Therefore, the output impedance ofthe drive electrode driver 16R increases due to the time constant of theinterconnects for connecting these units, and possibly the driving forceof the drive electrode driver 16R is limited.

In contrast, in the display device 1 according to the presentembodiment, the common drive electrodes COML are so formed as to beextended along the same direction as that of the pixel signal lines SGL.Therefore, always writing is performed in only one sub-pixel SPix of thesub-pixels SPix connected to a respective one of the common driveelectrodes COML. Thus, the total load of the common drive electrode COMLin the display unit 20 does not change depending on whether or notwriting is performed and is the sum of the heavy capacitive load of onesub-pixel SPix in which the writing operation is carried out and thelight capacitive loads of the other sub-pixels SPix. That is, the loadof the common drive electrode COML is smaller than that in the displaydevice 1R. Therefore, the drive electrode driver 16 does not need strongdriving force equivalent to that in the display device 1R, so thatincreases in the circuit area and the power consumption can besuppressed.

Furthermore, in the display device 1 according to the presentembodiment, as shown in FIGS. 6A and 6B, the drive electrode driver 16is formed in the COG 19 together with the drive signal generator 15 andcan be disposed at a position close to the terminal part T, to whichpower is supplied. Thus, the length of the interconnects for connectingthese units can be set short and the lowering of the driving force ofthe drive electrode driver 16 can be suppressed.

FIGS. 14A and 14B show results of simulation about the capability ofwriting to the pixel in the display device 1 according to the presentembodiment and the display device 1R according to the presentcomparative example. In the simulation of FIGS. 14A and 14B, thereaching time from application of the pixel signal Vpix to the pixelsignal line SGL by the source driver 13 and the selection switch unit 14to the timing when the potential difference between the pixel signalVpix and the drive signal Vcom (pixel potential) in a certain sub-pixelSPix reaches a predetermined potential is used as the index forevaluating the writing capability. FIG. 14A shows the reaching time ofthe pixel potential in the sub-pixel SPix close to the drive electrodedriver 16. FIG. 14B shows the reaching time of the pixel potential inthe sub-pixel SPix around the center of the display surface. In thisexample, the display device 1 according to the present embodiment has aconfiguration like that shown in FIG. 6B and the common drive electrodeCOML is driven from both sides of the display unit 20. That is, FIG. 14Ashows the data of the sub-pixel SPix in which the reaching time is theshortest. FIG. 14B shows the data of the sub-pixel SPix in which thereaching time is the longest.

As shown in FIGS. 14A and 14B, the reaching time in the display device 1according to the present embodiment is half that in the display device1R according to the present comparative example. That is, in the displaydevice 1 (FIG. 6B), the reaching time is shorter although the commondrive electrode COML is longer compared with the display device 1R (FIG.11). This is because of the following reasons. Specifically, asdescribed above, in the display device 1, the total load from theviewpoint of the common drive electrode COML is lighter compared withthe display device 1R and the respective distances among the driveelectrode driver 16, the drive signal generator 15, and the terminalpart T are shorter compared with the display device 1R. Due to thesefeatures, in the display device 1, driving of the common drive electrodeCOML by the drive electrode driver 16 is facilitated and the reachingtime can be shortened.

Advantageous Effects

As described above, in the present embodiment, the common driveelectrodes COML are so formed as to be extended along the same directionas that of the pixel signal lines SGL and the drive signal Vcom issupplied from each of the different common drive electrodes COML to arespective one of the sub-pixels SPix in one horizontal line in whichwriting is performed. This can reduce the possibility that noise ismixed from the other sub-pixels SPix in this one horizontal line via thecommon drive electrode COML and can suppress the deterioration of theimage quality.

Furthermore, in the present embodiment, writing is performed for onlyone sub-pixel SPix of the plural sub-pixels SPix connected to arespective one of the common drive electrodes COML. Thus, the capacitiveload component of the display unit from the viewpoint of the commondrive electrode COML can be set small and driving of the common driveelectrode COML by the drive electrode driver can be facilitated.

In addition, in the present embodiment, the drive electrode driver isdisposed at a position close to the display unit, the drive signalgenerator, and the terminal part T. Thus, the time constant of theinterconnects among these units can be set small and driving of thecommon drive electrode COML by the drive electrode driver can befacilitated.

Modification Example 1-1

In the above-described embodiment, the respective common driveelectrodes COML are each directly connected to the drive electrodedriver 16 via the drive electrode line part 29. However, theconfiguration is not limited thereto. Instead of this, the common driveelectrodes COML may be connected to the drive electrode driver 16 via aswitch as shown in FIG. 15 for example. In the example of FIG. 15, thisswitch (drive electrode switch SWCOM) is composed of three switches. Oneterminals of these switches are connected to each other and suppliedwith the drive signal Vcom from the drive electrode driver 16 and theother terminals are connected to the common drive electrodes COML of thedisplay unit 20. In this example, for example three switches in eachdrive electrode switch SWCOM are sequentially turned to the on-state ina time-division manner, and thereby the drive electrode driver 16 cansupply the drive signal Vcom to each of the common drive electrodesCOML.

Modification Example 1-2

In the above-described embodiment, the drive signal Vcom is supplied inunits of the sub-pixel SPix. However, the configuration is not limitedthereto. Instead of this, the drive signal Vcom may be supplied in unitsof the plural sub-pixels SPix for example. Several examples will bedescribed below.

FIGS. 16A and 16B show configuration examples when the drive signal Vcomis supplied in units of the pixel Pix. FIG. 16A shows a configurationexample in which, of the common drive electrodes COML formed on eachsub-pixel SPix basis, three common drive electrodes COML relating to thesame pixel Pix are connected to each other (drive electrode line part29B) and connected to the drive electrode driver 16. FIG. 16B shows aconfiguration example in which the common drive electrodes COML eachcorresponding to the width of the pixel Pix (three sub-pixels SPix) areformed and connected to the drive electrode driver 16 via a driveelectrode line part 29C. These configurations allow the drive electrodedriver 16 to supply the drive signal Vcom in units of the pixel Pix. Inthis case, the dot-inversion driving for the display unit 20 is not thesub-pixel-inversion driving, in which the polarity is inverted on eachsub-pixel SPix basis, described for the above-described embodiment butpixel-inversion driving in which the polarity is inverted on each pixelPix basis.

FIG. 17 shows one configuration example when the drive signal Vcom issupplied in units of two pixels Pix. The common drive electrodes COMLeach corresponding to the width of two pixels Pix are formed andconnected to the drive electrode driver 16 via a drive electrode linepart 29D. This configuration allows the drive electrode driver 16 tosupply the drive signal Vcom in units of two pixels Pix. In this case,the driving method for the display unit 20 is inversion driving in whichthe polarity is inverted every two pixels Pix.

Modification Example 1-3

In the above-described embodiment, the display unit 20 is driven basedon the dot-inversion driving. However, the configuration is not limitedthereto. Instead of this, the display unit 20 may be driven based onso-called line-inversion driving like that shown in FIGS. 18A and 18Bfor example. In FIGS. 18A and 18B, FIG. 18A shows the polarities of thepixel potentials for the sub-pixels SPix in a certain frame. FIG. 18Bshows the polarities of the pixel potentials in the next frame. As shownin FIGS. 18A and 18B, in the line-inversion driving, the display unit 20is so driven that, in a certain frame, the polarities of the pixelpotentials of the sub-pixels SPix adjacent to each other along the rowdirection are identical to each other and the polarities of the pixelpotentials of the sub-pixels SPix adjacent to each other along thecolumn direction are different from each other. Furthermore, thepolarities of the pixel potentials of all of the sub-pixels SPix areinverted on a frame-by-frame basis.

Other Modification Examples

In the above-described embodiment, the pixel signal Vsig is configuredby time-division multiplexing of the pixel signals Vpix of threesub-pixels SPix. However, the configuration is not limited thereto.Instead of this, the pixel signals Vpix of four or more sub-pixels SPixor two sub-pixels SPix may be subjected to the time-divisionmultiplexing for example. In this case, the number of switches in eachswitch group 17 of the selection switch unit 14 is set equal to thenumber of sub-pixels SPix as the multiplexing subject.

In the above-described embodiment, the source driver 13 supplies thepixel signal Vsig to the selection switch unit 14 and the selectionswitch unit 14 separates the pixel signals Vpix from the pixel signalVsig and supplies the pixel signals Vpix to the display unit 20.However, the configuration is not limited thereto. Instead of this, thesource driver may generate the pixel signals Vpix and supply themdirectly to the display unit 20 without the provision of the selectionswitch unit 14 for example.

2. APPLICATION EXAMPLES

With reference to FIG. 19 to FIG. 23G, application examples of thedisplay device described for the above-described embodiment andmodification examples will be described below. The display device of theabove-described embodiment and so forth can be applied to electronicapparatus in every field, such as a television device, a digital camera,a notebook personal computer, a portable terminal device typified by acellular phone, and a video camcorder. In other words, the displaydevice of the above-described embodiment and so forth can be applied toelectronic apparatus in every field that displays a video signal inputfrom the external or a video signal generated inside as image or video.

Application Example 1

FIG. 19 shows the appearance of a television device to which the displaydevice of the above-described embodiment and so forth is applied. Thistelevision device has e.g. a video display screen part 510 including afront panel 511 and a filter glass 512, and this video display screenpart 510 is formed of the display device according to theabove-described embodiment and so forth.

Application Example 2

FIGS. 20A and 20B show the appearance of a digital camera to which thedisplay device of the above-described embodiment and so forth isapplied. This digital camera has e.g. a light emitter 521 for flash, adisplay part 522, a menu switch 523, and a shutter button 524, and thisdisplay part 522 is formed of the display device according to theabove-described embodiment and so forth.

Application Example 3

FIG. 21 shows the appearance of a notebook personal computer to whichthe display device of the above-described embodiment and so forth isapplied. This notebook personal computer has e.g. a main body 531, akeyboard 532 for input operation for characters, etc., and a displaypart 533 that displays images, and this display part 533 is formed ofthe display device according to the above-described embodiment and soforth.

Application Example 4

FIG. 22 shows the appearance of a video camcorder to which the displaydevice of the above-described embodiment and so forth is applied. Thisvideo camcorder has e.g. a main body part 541, a lens 542 that isprovided on the front side of this main body part 541 and used forsubject photographing, a start/stop switch 543 used in photographing,and a display part 544. This display part 544 is formed of the displaydevice according to the above-described embodiment and so forth.

Application Example 5

FIGS. 23A to 23G show the appearance of a cellular phone to which thedisplay device of the above-described embodiment and so forth isapplied. For example, this cellular phone is formed by connecting anupper case 710 to a lower case 720 by a connecting part (hinge part) 730and has a display 740, a sub-display 750, a picture light 760, and acamera 770. The display 740 or the sub-display 750 is formed of thedisplay device according to the above-described embodiment and so forth.

The present disclosure has been described above by taking embodiment,modification examples, and examples of application to electronicapparatus. However, the present disclosure is not limited to theembodiment and so forth and various modifications are possible.

For example, in the above-described embodiment and so forth, the displayunit 20 is configured by using a liquid crystal of any of various kindsof modes such as TN, VA, and ECB modes. However, instead of this, aliquid crystal of a transverse electric field mode such as a fringefield switching (FFS) mode or an in-plane switching (IPS) mode may beused. For example, if a liquid crystal of the transverse electric fieldmode is used, a display unit 90 can be configured as shown in FIG. 24.FIG. 24 shows one example of the sectional structure of the major partof the display unit 90 and shows the state in which a liquid crystallayer 6B is interposed between a pixel substrate 2B and a countersubstrate 3B. The names, functions, and so forth of the other respectivecomponents are the same as those in FIG. 3 and therefore descriptionthereof is omitted. In this example, the common drive electrode COML isformed just on the TFT substrate 21 and forms part of the pixelsubstrate 2B differently from the case of FIG. 3. The pixel electrode 22is disposed over the common drive electrode COML with the intermediaryof an insulating layer 23.

For example, in the above-described embodiment and so forth, a liquidcrystal display element is used as the display element. However, theconfiguration is not limited thereto. Instead of this, any displayelement such as an electro luminescence (EL) element may be used.

The present disclosure contains subject matter related to that disclosedin Japanese Priority Patent Application JP 2010-187222 filed in theJapan Patent Office on Aug. 24, 2010, the entire content of which ishereby incorporated by reference.

What is claimed is:
 1. A display device comprising: a plurality ofsignal lines respectively extending along a direction; a plurality ofcommon drive electrodes respectively extending in the direction of thesignal lines; a plurality of display elements, one of the displayelements being directly electrically connected to a drain of atransistor, a source of the transistor being directly electricallyconnected to one of the signal lines, said one of the display elementsbeing directly electrically connected to one of the common driveelectrodes that makes a pair with said one of the signal lines, scandriving of the display elements being performed in the direction of thesignal lines; and a drive electrode driver, respective ones of theplurality of common drive electrodes connected to the drive electrodedriver via a drive electrode switch, wherein the drive electrode switchincludes a plurality of switches which are sequentially operated in atime-divisional manner, a predetermined number of display elementsconstitute a single display pixel, a width for each of the common driveelectrodes corresponds to a respective width for each of the displayelements, respective first ends of a predetermined number of switches,which correspond to the predetermined number of display elementsincluded in the single display pixel, are connected to each other, andrespective second ends of the predetermined number of switches areconnected to a corresponding common drive electrode, the drive electrodedriver is connected to the respective first ends of the predeterminednumber of switches and supplies a drive signal to the respective firstends of the predetermined number of switches, and the plurality ofswitches are operated in units of display elements.
 2. The displaydevice according to claim 1, wherein said one of the common driveelectrodes is so formed as to make a pair with a predetermined number ofthe signal lines.
 3. The display device according to claim 2, whereineach of the predetermined number of the display elements configure to adisplay pixel includes one red display element, one green displayelement, and one blue display element.
 4. The display device accordingto claim 1, wherein each of the display elements is a liquid crystaldisplay element.
 5. The display device according to claim 1, wherein thedrive electrode driver is configured to be disposed at a sideintersecting with an extending direction of the plurality of commondrive electrodes and drive the plurality of common drive electrodes, andfurther comprising: a terminal part configured to be disposed at theside at which the driver is disposed and supply a signal to the driver.6. The display device according to claim 1, wherein each of the displayelements is directly electrically connected to said one of the commondrive electrodes.
 7. The display device according to claim 1, whereinthe drive electrode driver and the drive electrode switch respectivelysupply drive signals with polarities opposite to each other to commondrive electrodes adjacent to each other.
 8. The display device accordingto claim 7, further comprising a source driver connected to theplurality of signal lines via a selection switch unit, wherein thesource driver and the selection switch unit respectively supply pixelsignals with polarities opposite to each other to signal lines adjacentto each other.
 9. The display device according to claim 8, wherein adot-inversion driving is performed by supplying the drive signals withpolarities opposite to each other to common drive electrodes adjacent toeach other and supplying the pixel signals with polarities opposite toeach other to signal lines adjacent to each other.
 10. A display devicecomprising: a plurality of signal lines respectively extending along afirst direction; a plurality of drive electrodes respectively extendingin the first direction; a plurality of display elements configured to besubjected to scan driving in the first direction, wherein one of thesignal lines is directly electrically connected to a source of atransistor, a drain of the transistor is directly electrically connectedto one of the display elements, and said one of the display elements isdirectly electrically connected to one of the drive electrodes; and adrive electrode driver, respective ones of the plurality of driveelectrodes connected to the drive electrode driver via a drive electrodeswitch, wherein the drive electrode switch includes a plurality ofswitches which are sequentially operated in a time-divisional manner, apredetermined number of display elements constitute a single displaypixel, a width for each of the drive electrodes corresponds to arespective width for each of the display elements, respective first endsof a predetermined number of switches, which correspond to thepredetermined number of display elements included in the single displaypixel, are connected to each other, and respective second ends of thepredetermined number of switches are connected to a corresponding driveelectrode, the drive electrode driver is connected to the respectivefirst ends of the predetermined number of switches and supplies a drivesignal to the respective first ends of the predetermined number ofswitches, and the plurality of switches are operated in units of displayelements.
 11. The display device according to claim 10, furthercomprising: a terminal part configured to be supplied with power; aplurality of scan signal lines respectively extending along a seconddirection; and a gate driver configured to supply a scan signal to theplurality of scan signal lines, wherein the drive electrode driver isconfigured to supply a drive signal to the drive electrodes, and isdisposed at a position closer to the terminal part than the gate driver.12. The display device according to claim 10, wherein each of thedisplay elements is directly electrically connected to eachcorresponding one of the drive electrodes.
 13. An electronic apparatuscomprising: a display device; a controller configured to controloperation carried out by utilizing the display device, wherein thedisplay device includes: a plurality of signal lines respectivelyextending along a direction, a plurality of common drive electrodesrespectively extending in the direction of the signal lines, and adisplay element that is inserted and connected between one of the signallines and one of the common drive electrodes that make a pair with eachother, and is subjected to scan driving in the direction of the signallines, wherein said one of the signal lines is directly electricallyconnected to a source of a transistor, a drain of the transistor isdirectly electrically connected to one of the display elements, said oneof the display elements is directly electrically connected to said oneof the common drive electrodes; and a drive electrode driver, respectiveones of the plurality of common drive electrodes connected to the driveelectrode driver via a drive electrode switch, wherein the driveelectrode switch includes a plurality of switches which are sequentiallyoperated in a time-divisional manner, a predetermined number of displayelements constitute a single display pixel, a width for each of thecommon drive electrodes corresponds to a respective width for each ofthe display elements, respective first ends of a predetermined number ofswitches, which correspond to the predetermined number of displayelements included in the single display pixel, are connected to eachother, and respective second ends of the predetermined number ofswitches are connected to a corresponding common drive electrode, thedrive electrode driver is connected to the respective first ends of thepredetermined number of switches and supplies a drive signal to therespective first ends of the predetermined number of switches, and theplurality of switches are operated in units of display elements.
 14. Theelectronic apparatus according to claim 13, wherein the display elementis directly electrically connected to said one of the common driveelectrodes.